Four crews from the Sumner, Woolston, Central and Governors Bay stations attended the 40m x 10m blaze near Evans Pass Rd about 3.30am.
Sumner Volunteer Fire Brigade chief fire officer Daryl Sayer said the blaze was quickly put out - but crews stayed for about an hour to make sure it did not flare up in dry areas.
A similar early morning blaze happened on the same road last Tuesday.
Police are investigating both fires, which have been deemed suspicious.
It is the third large suspicious fire in the Port Hills area this month.
On February 12, fire crews battled three fires which burnt through 6ha of native reserve off Tunnel Rd (State Highway 74) in Heathcote, between Port Hills and Ferry Rds.
Fire investigators will be at the scene of this morning's on Monday.
Fire and Emergency New Zealand fire investigator Wayne Hamilton said anyone with information about any of the blazes should phone police on 105.
He thanked the public for alerting FENZ to the fire.
However, the blaze acts as a timely reminder that, although the city received a small amount of rain over the weekend, conditions are still very dry.
Said Mr Sayer: "My concerns are that [these fires] are damaging walking tracks and the wildlife and plant life that goes with those.
"But more concerning is that, even though we have good safety measures in place, we may end up with our personnel becoming injured as a result of this thoughtless action."
